Magnetic recording device

According to one embodiment, a magnetic recording device includes a magnetic head and a controller. The magnetic head includes first and second magnetic poles, a magnetic element provided between the first and second magnetic poles, and first and second terminals. The controller is configured to perform a recording operation. In the recording operation, the controller is configured to supply a recording current to the coil while applying an element voltage not less than a first voltage and not more than a second voltage between the first terminal and the second terminal. A differential resistance of the magnetic element when a positive applied voltage applied between the first terminal and the second terminal is changed while the recording current is supplied to the coil becomes a first peak when the applied voltage is the first voltage.